Research participants are entitled to many rights that may easily come into conflict. The most important ones are that researchers respect their autonomy as persons and act on the principles of beneficence, nonmaleficence, and justice. Since 2014, research subjects from numerous states in the United States of America also have a legal “right to try” that allows them, under certain circumstances, to receive experimental (i.e., preliminarily tested) interventions, including medical devices, before official approval from the United States Food and Drug Administration. In the context of experimental interventions, such as deep brain stimulation (DBS) for Alzheimer’s disease, this article argues that research participants ought never to have a legal “right to try” without a corresponding “right to be sure.” The latter refers to external epistemic justification construed in terms of reliance on reliable evidence. This article demonstrates that the mere complexity of intervention ensembles, as in the case of DBS for Alzheimer’s disease which serves as a paradigm example, illustrate how unanswered and/or unasked open questions give rise to a “combinatorial explosion” of uncertainties that require epistemic responses that no single research team alone is likely able to provide. From this assessment, several epistemic asymmetrical relations between researchers and participants are developed. By elucidating these epistemic asymmetries, this article unravels the reasons why open science, transparent exhaustive data reporting, preregistration, and continued constant critical appraisal via pre- and postpublication peer review are not scientific virtues of moral excellence but rather ordinary obligations of the scientific work routine required to increase reliability and strength of evidence.